Perennial. Stems slender, twining, thinly pubescent. Leaves shortly petioled, oblong to linear-oblong, oblong-lanceolate or lanceolate, firm, thinly pubescent, 1–2 in. long, narrowed to the base, obtuse with a small mucro. Peduncles 1-flowered, 1–1 1/2 in. long; bracts minute, lanceolate. Calyx 6–8 lin. long in flower, becoming 9 lin. long in fruit; outer sepals ovate, obtuse, becoming scariose; inner lanceolate. Corolla white, densely hairy on the ribs, regularly funnel-shaped, 1 in. long. Capsule ovoid, glabrous, as long as the calyx, 4-valved. Seeds glabrous, black, punctulate, with short flat hairs on the edges, 2 1/2 lin. long, as large as a pea.